Bending means for sinuous spring strips



Jan. 25, 1955 BENDING MEANS Filed May 25. 1951 4 Sheets-Sheet l Jan. 25, 1955 o. wElss 2,700,409

BENDING MEANS FOR SINUOUS SPRING STRIPS Filed May 25, 1951 4 Sheets-Sheet 2 1N VEN TOR. @jaar Wells-5,

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Jan. 25, 1955 o. wElss v2,700,409

BENDING MEANS FoR srNuous SPRING STRIPS f Filed May 25, 1951 4 Sheets-Sheet 5 n wa /a 7 /A 39 K INVENTOR. v E E l @564/ Wallis,

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Jan. 25, 1955 o. wElss 2,700,409

\ BENDING .MEANS FOR SINUoUs SPRING STRIPS Filed May 25. 1951 4 Sheets-Sheet 4 A I N V EN TOR. 05624;" jfl/6x55,

BENDING MEANS FOR SINUOUS SPRING STRIPS Oscar Weiss, Detroit, Mich., assignor, by mesne assignments, to No-Sag Spring Company, a corporation of Michigan Application May 25, 1951, Serial No. 228,212

7 Claims. (Cl. 153-54) This invention relates to spring making machines and more particularly to machines for forming wire springs having a plurality of sinuous lateral turns and a preset longitudinal arch.

As is well known, the conventional machine for forming such longitudinally arched flat springs includes a forming mechanism which introduces the sinuous lateral turns and simultaneously introduces a longitudinal arch of predetermined radius to the stock. The stock then passes to a reforming mechanism which changes the radius of the longitudinal arch according to the desired spring characteristics, either increasing or decreasing the radius of curvature depending upon the desired nal shape of the spring. Finally, the stock is fed to a cutting mechanism which severs predetermined lengths of stock to make the nal product.

This invention relates particularly to the reforming mechanism in such spring making machines. In the reforming mechanisms presently used, such as that described in Reissue Patent No. Re. 23,169, reissued November 22, 1949, to Frank I. Horton, there are several inherent disadvantages which greatly decrease the flexibility and etliciency of the entire machine. The range of radii of curvature which can be formed by the conventional reforming mechanism does not' permit the formation of springs having relatively large radii of curvature, that is, approaching a at spring. Moreover, the present reforming mechanisms are not easily adjustable, and due to their complicated construction are liable to frequent failure and breakage.

It is an object of the present invention to eliminate the disadvantages of the present reforming mechanisms,

ited States Patent-O and to provide a novel and improved reforming mechanism which is highly versatile and which can form springs over a large and continuous range of vcurvatures, up to and including a iiat spring.

It is another object to provide an improved reforming mechanism which is easily adjustable by the operator, and which is of relatively simple construction and is not subject to failure or breakage.

It is a further object to provide a reforming mechanism of the above character, which comprises a pair of complementary rollers between which the formed spring is fed, and an adjustable guide for maintaining the stock in engagement with a predetermined peripheral portion of one or the other of said rolls, whereby the curvature of the stock may be either increased or decreased over a continuous range. Y

It is another object to provide a reforming mechanism of the above character, in which the complementary rollers are relatively adjustable, so as to accommodate different wire gauges and different pitches or looped spacings, and to facilitate removal of jammed wire in cases of stock breakage.

It is a further object to provide a reforming mechanism of the above character, having a novel Vand improved guide means at the delivery side of the reforming rollers, which eliminates the possibility of jamming or bunching of the wire at this guide station in cases of interruption of the wire feeding process.

Other objects, features, and advantages of the present invention will become apparent from the subsequent description taken in conjunction with the accompanying drawings.

In the drawings:

Figure 1 is a side elevational view ofv a spring making machine embodying the improved reforming mechanism ICC of this invention, parts being broken away and in crosssection for clarity. l

Figure 2 is a front elevational view of the reforming mechanism, taken in the direction of the arrow 2 in Fig. 1, with a portion of the main frame shown in dotdash lines.

Figure 3 is a fragmentary cross-sectional view taken along the line 3-3 of Fig. 1 and showing the cooperation of the reforming rollers.

Figure 4 is a fragmentary cross-sectional view taken along the line 4--4 of Fig. 1 and showing the construction of the shoe adjusting means.

Figure 5 is a plan view of the reforming mechanism and showing the driving means for the indexing or sprocket roller.

Figure 6 is a fragmentary cross-sectional View taken along the line 6-6 of Fig. 1 and showing the construction of the guide shoes.

Figure 7 is a fragmentary cross-sectional view taken along the line 7-7 of Fig. 1 and showing the locking means for the shoe adjusting means.

Figure 8 is a detail view in side elevation of a shoe suppiorting ring and its corresponding crescent-shaped trac Figure 9 is a front view of the parts shown in Fig. 8, partly in cross-section along the line 9 9 of Fig. 8.

Figure 10 is a side elevational view of the reforming mechanism, parts being broken away for clarity.

Figure 11 is a fragmentary cross-sectional view taken along the line 11-11 of Fig. 5 and showing the adjusting means for the idler roller; and

Figure 12 is a fragmentary cross-sectional view taken along the line 12-12 of Fig. 1l and showing the locking means for the idler roller adjusting means.

The reforming means of the present invention is shown as applied to a spring making machine of a type such as that of the aforementioned patent used in fabricating longitudinally arched springs having sinuous lateral turns, although it will be understood that the principles embodied in the reforming mechanism are equally applicable to other types of strip forming machines. The machine in the illustrated embodiment is of the type shown, for example, in Patent No. 2,188,407 issued on January 30, 1940, to Frank I Horton, and comprises in general a conditioning mechanism for preconditioning the wire stock, and a forming wheel having two sets of alternately spaced radial fingers which cooperate with reciprocating cams to form the sinuous lateral turns, the stock being held against a portion of the wheel periphery to introduce a predetermined longitudinal arch in the stock.

The invention comprises, in general, a pair of complementary rollers between which the stock passes after it leaves the forming wheel, one of said rollers being intermittently indexed by power means, the other being an adjustable idler roller. The invention further comprises a pair of spaced guide shoes which are adjustable about an axis parallel to but spaced from the axes of the two reforming rollers, the spring stock passing between these guide shoes before it enters the rollers. The guide shoes are adjustably held in a selected position so that the stock engages either one or the other of said rollers over a predetermined portion of its periphery. This forced engagement causes the stock to either lose some or all of its curvature or to increase its curvature,.de pending upon which roller is engaged and what portion of the roller is engaged.

Referring more particularly to the drawings, the spring making machine receives the unformed wire 21 from a conditioning mechanism (not shown), the supporting bracket 22 of which is fragmentarily shown in Fig. l. The wire passes through suitable guides 23 and 24 mounted on the .main frame 25 of the machine. The forming wheel 26, which is mounted on the frame by shaft 2'7, receives the wire at its upper portion. The forming wheel is indexed intermittently at a predetermined rate by a worm 2S driven by a shaft 29, the worm having a dwell portion during which rotation of wheel 26 momentarily stops. The Wheel has a plurality of radially movable pins 31 which are arranged in two axially spaced sets, the pins of the two sets being in staggered relation. These pins are projectable outwardly from the -bentwire for its next bending movement in thefopposite direction. The sinuouslybentwireis then carriedunder ya forming shoe 33 concentric with Athe'wheelf26,the arcuate shape of the forming shoe imparting a"long itudinal arch ,to the wire as it passes thereunder. The arched wire 34 containing the sinuous lateral turns'is" thencarried downwardly through a guide chute 35 to the reforming mechanism,' where'thecurvature of its longitudinal arch is either increased or decreased. It will be understood that the forming mechanismjust'described in itself isconventional and that'other types of forming-'mechanisms could be used in conjunction with the invention.

The improved reforming mechanism comprises,` in,y general, an Vindexing or'sprocket rollergenerally indicated at 36 whichis intermittently power driven, anidler roller generally indicated at 37 which isadjacent the-sprocket Vroller and is indirectly supported bythe main frame, and

locating mechanism generally indicated at 33 which guides the path of the stock-throughrollers36iand 37. Extending vdownwardly-and outwardly from'the mainframe is a locating mechanismadjusting mechanismgenerally indicated at 39, the function of which is to rotatably adjust the locating'mechanism' 3S so as topredetermine the feeding angle of-the stock between rollers 36 andv 37 The mechanism further comprises adjustingmeansgenerally indicated at 4l for the idler roller, the function of this adjusting means being to vary the distance between the axes of rollers 36 and 37 Referring more particularly to the reforming rollers 36 and 37, these areV shown best in Figs. 2 and 3. The indexing or sprocket roller 36 is of generally -spool shape with an intermediate cylindrical portion 42 and oppositely disposed flange portions 43 Vand 44. A plurality of radially extending teeth 45 are'formed on the central portion of cylinder 42, the purpose of these teeth being to intert between the lateral turnsof the spring stock in order to feed the stock through the reforming rollers. These teethare, therefore, preferably of tapered shape, and are of less' height than the anges 43 and 44. The latter anges are preferably provided with downwardly and inwardly tapered walls-46 to facilitate the lateral positioning of the spring stock. j

As is best seen in Fig. 5, the -sprocket roller l36 is mountedron a power driven shaft 47 which extends outwardly from the frame of the machine, kand is driven by an intermittent drive through an intermediateV shaft 48. The intermittent drive may comprise a worm 49 driving a worm wheel 50 on shaft 48, this shaft also-carrying an intermediate gear 51 which drives pinion 52 on shaft 47. The worm 49 preferably has a dwell portion similar to worm 28 previously described so that' the shaft 47 is rotated in intermittent steps. It will be understood that other and similar driving means could'be used lfor the sprocket roller 36. The frame is provided with bearing portions 53 for supporting shaft 47 outwardly of the sprocket roller.

The idler roller 37 is mounted above and forwardly of the sprocket roller, and as is best seen in Fig. 3 this v roller comprises a pair of cylindrical portions 54 on opposite sides of a grooveSS, lthe groove being aligned with the teeth 45 of roller 36. A space l56 exists between the peripheral surfaces 54 of roller 37 and the peripheral surface 32 of roller 36, this space being sufficient to allow the wire spring stock to pass between the rollers and be r gripped thereby. Roller 37 is supported by a shaft 57, the bearing means for the roller being preferably a needle bearing 58. The opposite ends of shaft 57 are supported by arms 59 and 61 which form part of the adjusting mechanism 4l. These arms are held against lateral movement by guides 62 and 63 which, as will appear later, also serve as the tracks for the shoe supporting rings 64 and 65 respectively. The guides 62 and 63 are secured to the frame plates 66 and 67 respectively by a plurality of bolts 68. The upper ends of arms 59 and 61 are pivotally supported by pin 69 so that the arms may be rockably adjusted between guides 62 and 63. It will be observed, from an examination of Fig. l, that the position of pm 69 is such that the pivotal movement of arms 59 and 61 will cause roller 37 to move toward or 'away from roller 36. An oil hole 71 may be provided in groove f55- of roller 37^ to` permit lubrication lof needle bearing 58.

The locating mechanism 38 is mounted for arcuate movement around rollers i36 and 37. This mechanism comprises a pair of shoes 72 and 73 having convex facing surfaces in spaced relation, the back surfaces of these members being of generally flat shape. The two shoes are secured between a pair of spaced shoe supporting plates 74fand 75 by atplurality of bolts 76. Plates 74 and 75 are integral with and extend from the shoe supporting rings 64' and 65 respectively, which rings as stated previously, are mountedon tracks 62 and 63. The plates 74 and 75 are spaced slightly inwardly from the planes of rings 64 and 65, so that the lateral dimension of shoes 72 and 73 is somewhat less than the lateral distance between tracks 62 and 63. `Shoe'72 is secured at a lesser radial distance from the axis of the shoe supporting rings than is shoe 73. Shoe 72 is also provided with a clearance Vslot `77 on its innerface for purposesof clearing the'sprocket teeth when theshoes are swung Vinto their rearward position. Y

In order that the shoe supporting rings 64 and-65 be capable of movement about an raxis spaced from the roller axes, the tracks' 62 andf'63 'are of generally crescent shape. Asis best `seen in Figs. 8 and9,each of these guides comprises an arcuate track surface 7S on its outer periphery which isflush with-the inner surface of its correspondingv shoe supporting ring. A flange 79 extends alongtheinnerside offthe-track surface 73 forV retaining the ring inlateral position. Theinner radiusib of each crescent shaped'. guide member is a clearance'recess concentric with the sprocket'roller 36, these recesses being similar-to recesses'ion frame plates'66 andf67. The tracks are secured to fram'eiplates 66 and` 67 in such kposition that the rings 64 and 65 rotate around an axis spaced forwardly from and between rollers 36 and 37. The consequence of this spacing is that as the shoes 72 and 73 are swung they will Vary their distance from the reforming roller. in particular, when the shoes are in a rearward'positionl asshown'inFig. '10, they will be relatively close to sprocketiroller 36. As the shoes 72 and 73 are swung in a clockwise direction, theyv will decrease their distance from roller 36,' as shown in Fig. l. When the.' shoes 72' and 73 are in their extreme forward position, :they will be equidistant from both rollers 36 and 37'and`as theyfare `swungupwardly from their forward position they will approach'roller 37. It will be observed thatgsince the shoe 72 is closer tothe ring' axis than is shoe 73, shoe 72 will be closer to roller 37 when the shoes are inftheir upper position. This is of importance since, asv will beseen later, the spring stock rides against shoe 73'when 'the-locating mechanism 38 is in its downward and rearward position rides against shoe 72 when the mechanism is in its upper or forward position.

Meansare'provid'ed lfor adjustably securing the locating mechanism 38 'in any'desiredpredetermined position with respect to rollers 36 and 37. `lFor this purpose, the outer periphery of ring 65 is provided with a plurality of adjustingnotches'SZ whichextend'peripherally around a major segment of the ring. These adjusting notches arel designed to cooperate; withanadjusting member 83 adjacent ring 65. Adjustingmember 83 is of arcuate shape and is provided with-.a projection-184 at an intermediate portion of its innersurfa'cey the' projection beingy adapted yto be inserted in a selected notch '82*to engage the-'ring for rotary movement. The adjusting member is supported between 'uterfframe plate 67 and a retaining plate 85 which is secredin spaced parallel relation with plate 67. The outer'surface 86 of 'the adjusting' member 33 is engageable withan upper stationaryguide 87 and a lower lguide v88,"these guides also serving as limiting stops, as will be seen, for the arcuate movement of the adjusting member. The lower end of the adjusting member is provided witharrfinclinedcam surface 89 which cooperates with a retractingcam' 91`secured at a lower portion of the frame. It willfbe seen from'Fig. l0 that when the holding'rnember-83 is I4swung downwardly a sufficient distance, the engagement of cam-'surface`89 with cam 91 will cause outwardmovement ofprojection 84 from a particular slot 82 with :which it is engaged.

`The adjusting member has-an ear 92 projecting radially outwardly from its intermediate portion, preferably opposite projection 84, and this ear is engageable by the adjustingfmemberliactutirrgneans 39, `as will'be-described later 86 of the adjusting member has a recess 93, and thisk recess is so positioned that it will come into alignment with guide 88 while cam surface 89 rides up on cam 91. It will, therefore,'be seen that while guides 87 and 88 will normally hold the adjusting member 83 against ring 65, the adjusting member will be allowed retracting movement when it reaches its lowermost position.

It will be observed that when projection 84 has entered a particular notch 82 in ring 65, arcuate movement of the adjusting member will cause corresponding arcuate movement of the ring and thus of shoes 72 and 73. The arc of movement of adjusting member 83 is limited by stop members 87 and 88 since ear 92 projects between the stop members. In the illustrated embodiment the arc of movement of the adjusting member 83 is about 60. -It will be noted that this arc of movement does not fully cover the total range of movement of shoes 72 and 73 since this range may include any position around the rollers except for a small segment directly to the rear of the rollers. The purpose of the plurality of notches 82 is, therefore, to allow the proper portion of the total range of movement to be preselected, the shoes then being adjustable in a limited area within this portion. The arrangement is preferably such that the portions will overlap, that is, the notches 82 are spaced closely enough so that the same shoe position can be obtained with two adjacent slots by different settings of the adjusting member 83.

The actuating means 39 for the adjusting member 83 is supported outwardly of the main frame of the machine by extensions of plates 66 and 67. In particular, plate 66 is secured inwardly of upright 94 of the main frame and extends forwardly and downwardly therefrom. Similarly, plate 67 is secured to upright 95 of the main frame by bolts 96 and extends forwardly and downwardly therefrom. rThe lower ends of these extensions are secured together by a bolt 97 which is surrounded by a spacer 98, holding the extensions in rigid parallel relation. As is best seen in Figs. 3 and 4, a guide plate 99 is secured inwardly of the extension of plate 67, the guide plate 99 being spaced from plate 67 by spacing members 101 and 102. An actuating slide 103 is disposed between the plate 67 and the guide plate 99, the slide being constrained to sliding movement by these two plates and by the spacer plates 101 and 102. The slide 103 extends upwardly between these guide surfaces and the upper portion thereof is provided with a notch 104 for the reception of projection 92 on the adjusting member 83. It will, therefore, be seen that since the sliding movement of slide 103 is approximately tangent to the adjusting member 83, such movement will result in arcuate movement of the adjusting member. The depth of notch 104 is such that projection 92 may move back and forth within the notch during this arcuate movement.

The lower portion of actuating slide 103 is provided with a laterally extending nut member 105, this nut member extending through an elongated clearance aperture 106 in plate 67, and being fastened to the` slide 103 by bolts 107. Nut 105 receives an adjusting screw 108 which is rotatably mounted on plate 67 outwardly of aperture 106 by mounting brackets 109 and 111. A hand wheel 112 is provided at the lower end of screw 108, so that rotation of the hand wheel will cause nut 105 to move up or down within aperture 106, thereby actuating the slide 103.

A stop is provided for limiting the downward movement of slide 103, so as to prevent engagement of cam surface 89 of the adjusting member 83 with retracting cam 91. This stop means comprises a blocking member 113 pivotally mounted on bracket 109 by a pin 114. As is best seen in Figs. and 7, blocking member 113 has a hook shape and is adapted to partially surround screw 108 when the stop is in its downwardly inclined operative position. When in this position, the nut 105 will thus be prevented from reaching the lowermost end of the screw. The arrangement is such that only when nut 105 reaches the very end of the screw 108 will cam surface 89 engage the retracting cam 91. It will, therefore, be seen that in order to release the shoes 72 and 73, it is necessary to positively move stop member 113 out of its normal operative position, and this will prevent accidental movement of the adjusting shoes during operation of the machine.

Means are also provided for locking the adjusting screw 108 in any predetermined position, when it is desired to operate the machine in this position for an extended period. As is best seen in Fig. 7, this locking means comprises relatively movable annular elements 115 and 116 mounted within screw supporting bracket 109 and engageable with the screw 108. These annular members are relatively movable by a locking bolt 117 which is threadably engageable with element 115, the latter element being fixed within an aperture 118 in bracket 109. Rotation of locking bolt 117 will, therefore, cause members 115 and 116 to draw together, thus jamming screw 108 and preventing rotation thereof.

As best seen in Figs. 7 to 14, the adjusting means 41 for varying the distance of idler roller 37 from sprocket 36 is secured to the main frame of the machine above the idler roller by means of bolts 119 and 121. The adjusting means comprises a forked rocking member 122 pivoted between plates 66 and 67 by removable pin 69. The lower arms of the rocking member comprise the supports 59 and 61 for the idler roller shaft 57, and are disposed between the crescent shaped guides 62 and 63, as seen in Fig. 3. The upper arm 124 of the rocking member is integral with the lower arms and extends upwardly to a clevis 125, being pivotally secured thereto by a pin 126 which extends through a slightly elongated aperture in the arm 124. Clevis has a threaded portion 127 which is threadably engaged by an adjusting screw 128 rotatably mounted in a bracket 129. This bracket, which is supported by bolts 119 and 121, is disposed between the upper portion of plates 66 and 67 and contains a locking mechanism 131 for adjusting screw 128, this locking mechanism being similar to that of shoe adjusting screw 108. It will, therefore, be seen, especially from Fig. ll, that rotation from the end 132 of adjusting screw 128 by a wrench or other tool will cause clevis 125 to move to the left or right, thus swinging rocking member 122 about its pivot pin 69. This movement will cause the idler roller 37 to move toward or away from sprocket 36.

The adjusting means just described for the idler roller also permits this roller to be swung completely away from the sprocket 36, when it is desired to clear a wire jam or to change sprocket 36 for a sprocket of dilferent diameter. To carry out this operation, it is merely necessary to remove pin 69, after which the entire assembly of the rocker arm 122 and idler roller 37 maybe swung upwardly clockwise (in Fig. 10) about the clevis pin 126. The sprocket 36 may then be removed by movement in a radial direction, after withdrawal of shaft 47. The adjusta'bility of the idler roller has the further advantage of permitting the use of diierent gauges of wire since if the distance between the rollers were xed, the teeth 4S on the sprocket would not engage the wire loops when thin gauge wire was used.

After the reformed wire leaves the rolls 36 and 37 it rides onto a guide 135 which is disposedV immediately behind the two rollers. As is best seen inV Fig. l0, the guide 135 is of generally wedge shape and is secured to the frame of the machine by bolts 136. The narrow end 137 of the guide projects toward the space between the rollers and has an upwardly and rearwardly inclined guide surface 138. The main portion of the guide has a pair of oppositely disposed side walls 139 and 141 for lateral guidance of the spring. However, it will be noted, especially from Fig. 5, that there is no cover or upper wall on the guide, but rather that the space above the inclined guiding surface 138 is relatively unrestricted. This unrestricted space has the advantage of preventing piling-up or jamming of the wire spring within the guide when a break occurs, or when there is an unobstruction ahead of the moving spring, since with the improved construction the wire may freely curl up into the space above guide 135. It will be noted that the reason no cover plate is necessary on guide 13S Vis that the idler roller performs the function of such a cover in holding down the stock during the reforming operation.

After the wire spring leaves the guide 135, it moves under the cutting mechanism 142 driven by the crank arm 143 and the flywheel 144. The cutting mechanism cooperates with an anvil 145 mounted on the frame of the machine, and operates to cut the wire spring into the desired lengths. Automatic means for operating a cutting mechanism of this type is described in detail in aforementioned Patent No. 2,188,407. After leaving anvil 145, the lengths of wire Vspring are guided away from the machine by arcuate guide 146.

Before describing the operation in detail, it-may be observed that in general, when it is desired to increase `theV curvature'- ofi the stock, it isf held against:V4 aV predeteris-'vheld' against idleri iroller137. Since` the/maximum decrease incurvature'fto' be desiredw'ill-be that necessary to` 'produce`r a perfectly? flat Ikspring, there `exists moreI than -sutlicient-clearance forlfthe upper position-of the guide shoes. The extreme "increase-curvaturef position, y however, is limited by fthe-abutment 'of-'the guide shoes with the frame support for anvil 145,*vwhich isinobstructing relation with -the vpathof movement offthe guide-shoes. Theconstruction is, therefore,ipreferably such Aithat- Vthis`v extreme position willbe -ample-forany curvature of stock that mightbe-desired.

To-describe the operation, Lwe will assume -aninitial conditionlin' which-the 'shoes 72 and 73l are out of adjustment, and-are to be--adjustedto a position such asisshown in Fig.- 1-whereinanadditional amount of curvature -wi1l be imparted-to the stock. We will fur- 'ther-assumethat the adjusting-memberlSS is vengaged in' a particular notch 82,-fand -thatfit-y is desiredlto remove the adjusting member from this notch and lengage it-with another notch. `As the first step in the operation, the stop member -113 isswung out-of its blockingposition so that it isi spaced lfrom adjusting `screwltl. Hand 'wheel 112` is-"then rotated-in a direction so that nut -1'05 moves downwardly within aperture 4186. Thisaction will cause-slide 103 to move downwardly and to the left, as seen in Fig. 10. The rotation of the handwheel 112 is continued until nut 105l reaches the bottom-of the clearance aperture, -at-iwhich'time cam-surface-89 engages retracting-cam 91 to swing adjusting member 83 out of its engagement with notch 82, as shown in Fig.l l0. The shoes `72 and 73 may then-beswung manually, being supported 'for their swinging l movement by rings 64-and'165f ridingon tracks 62 and 63. In order that a particular notch 82 may be speedily aligned with projection -84 on the adjusting rnember83, the outerlfsurface of ring 6Svmay be provided with a plurality of vmarkings 147, as seen best inFig. 5, these markings cooperating -with one or more markings 148 on the interiorsurface of-plate 85. In particular, the markings may be-calibrated-for different radii of curvature, so thattheapproximate position of shoes 72 and 73 may be chosen. The handfwheel 112 is then rotated 'in the opposite direction, swinging adjustingmember 83 clockwise and engaging it 'with the newly chosenl notch 82. Theinut 105 may then-be adjustedto its proper height to locateshoes 72 and 73 at the exact desired positionyandvthesurfaceof plate 67 may be provided with markings 149 adjacent clearance aperture 10S-for this purpose. The'screw 108 may then be locked against further rotation by locking screw V117, and the stop :113 dropped back into its blocking position.

When the wire spring-stock is fed between the shoes 72 and 73, andv between thesprocket 36 and idler roller 37, rotation of shaft 47 by the intermittent driving means described above will cause the teeth 45 of the sprocket to engage the sinuous lateral turns 34. This actionV will draw the stock through the-shoes 72 and 73, the idler roller 37 preventing thestock from leaving the sprocket. Since the position of the shoes is such that the original curvature of the stock-is less than the curvature imparted to it between the shoes and the sprocket, the stock will ride against shoe 73 rather than shoe 72, as seen in Fig. l. The stock will thus be held against a predetermined portion of the periphery of sprocket 36, this forced retention of the stockagainst the surface of the sprocket imparting an increased curvature to the stock. It will be noted that the direct cause of the increased bending is the'coaction between the sprocket 36 and `the shoe 73, rather than the coaction of the sprocket with idler roller 37. In other words, the position of shoe 73 forces the stock to engage an arcuate portion of sprocket i36, and this forced engagement causes the increasedv curvature.

When it is desired todecrease the curvature 'of stock, the stock is forced against a predetermined peripheral portion of idler roller 37 rather than of sprocket 36. ln this case, 'ther shoes- 72- and 73 are 'swung into an upper position such as that shown by the dot-dash lines in Fig. l0. `When in'-thisposition,`the stock will engage the shoe 72 rather 1thantheishoe 73, since the position of theshoes frelativeto: the' 'idler roller is actually causing aV reverse'bending!v of thestock. "This reverse bending,

11H8 andi y'the#consequentengagement of the v-stockwithft-he peripheral lsurface fof. A'idler roller 37, rwill `result m a decreased curvature S-in; the'v nal product. If they lamount offreverse `bending isgreatcnough; the resultwillf'be lan entirelyatf'spring, since-all of the. original curvature -w-ill'ibe" forced 'outof the stock.

lt is important tofobservethat sincethe-shoes 72 Iand `73--are 'adjustablethroughout a continuous are, there is '-no fbl-ind sp'ot\fas1farasthenal curvature of the stock isvconcerned,b`ut that the'curvature may be chosen over a continuous rangefromran'A entirely'flat to an extremely sharp curvature. Toillustr'ate, if it is desired to retain the-'original curvature ofthe stock imparted by forming kwheel 26,'theshoes 72 and! 73 are adjusted to anfintermediatepositionfin'fwhich the stockfdoes-not positively `-engagefeither shoe 72'l or -73,but moves loosely therebetween. The stock -will thusnot -be held against-the periphery-of' either-roller, anditscurvature will not `be changed.

'While-itv/ill be apparent that the preferred embodiment ofthe invention herein disclosed is well calculated to fulll theobjects'i-above stated, it will be appreciated that the invention is susceptiblefto modication, variation -and change without departing from the proper scope or fair meaning 'ofthe'subjoined claims.

What iis claimed -is:

l. A mechanism-for reforming the longitudinal arch yin wire 'springs of `thetype having a pluralitj, of-sinuous -later'alfturnsand a longitudinal arch, said mechanism 'comprisinga power'driven sprocket roller, a complementary idlerroller, said rollers being adapted to receive the-springtherebetween, guide means for feeding the spring-at-'various' angularitics to said rollers, said guide means comprising a shoe slidably engageable by the spring, a supporting ring-forsaid shoe, and means for mounting saidsupporting ring for rotation about an axis parallel to said roller axes, whereby the spring may be heldfin engagement-with predetermined portions of the periphery of one of said'rollers.

' 2,'A mechanism foriforming a longitudinal arch in wire springs, comprising a pair of complementary rollers adapted to receive the-spring therebetween, guide means for holding the spring in engagement with a predetermined portionfof the'periphery of one or'the other of said rollers, a supportingring for said guide means, said ring beingmounted for rotation about an axis parallel to said roller axes, adjusting-'means forsaid ring, said adjusting lmeans `comprising an `-adjusting member outwardly adjacent said ring and-releasably engageable therewith, said 'adjusting membery being movablebetween a retracted positionout of engagement with said ring and an adjusting position in engagement with said ring, the ring being freely movable when the adjusting member is in its retracted position, and manualmeans for moving the adjusting 'member between its'positions "-3.'-Arnechanism for-forming a longitudinal arch in a wire spring, comprising a pair of complementary forming 'rollers adapted to receive `thespring therebetween, guide means yin 'spaced relation with said rollers for holding the springA against predetermined portions of the periphery of 'one or! the other ofsaid rollers, adjusting means for saidguide means, said adjusting means comprising a supportingring holding said guide means and mounted for rotation about an axis parallel to said rollers, said ringyhaving a plural-ityof spaced engaging portions on vitsrperiphery, an adjusting member outwardly adjacent Lsaid ring, said adjusting member having a complementary engaging-'portion releasably engageable with a selected engaging portion vonisaid ring, said adjusting member bc- `ing movable inan arcuate path to a'position in which it is retracted from engagement with said ring, whereby Vthe ring isfreelymovable to align a rselected engaging portion with said adjusting'member,'andrnanual means for moving said adjustingmember in its arcuatepath, whereby said'guidemeans'is'carried to various positions with respectto -said rollers.

- 4'. T he combination accordingto claim 3, said manuall means comprising a slide :engageable with a' portion of 'said' adjusting member, and a manually rotatable shaft for 'reciprocating said slide.

i 5.' The combination according to claim 3, further provided with blocking means for preventing the movement of said adjusting Amember into its retracted position.

6." AI mechanism 'fon-forming a' longitudinal-:arch iny a wire spring 'of v'the type having a plurality-'of sinuous lateral turns, said mechanism comprising a power driven sprocket roller having a plurality of radial teeth for engaging said lateral turns, an idler roller adjacent said sprocket roller, said idler roller having a clearance groove for said teeth, guide means for holding said spring against a predetermined portion of the periphery of one or the other of said rollers, said guide means comprising a pair of spaced shoes slidably engageable by the spring, and a pair of supporting rings for said shoes, said rings being mounted for rotation about an axis spaced to one side of and between said roller axes, whereby said shoes are movable between a position adjacent said sprocket roller and a position adjacent said idler roller.

7. The combination according to claim 6, further provided with mounting means for said supporting rings, said mounting rings comprising a pair of arcuate track plates, said idler roller being disposed between said plates.

References Cited in the file of this patent UNITED STATES PATENTS 

